215/35R17 vs 195/40R17
Going from one to the other changes the overall height by +0.9 %. That is inside the 3% band, so it fits and the speedometer stays close.
Side by side
| Measure | 215/35R17 | 195/40R17 | Change |
|---|---|---|---|
| Overall height | 22.9" | 23.1" | +0.9 % |
| Sidewall | 2.96" | 3.07" | +3.7 % |
| Section width | 215 mm | 195 mm | -9.3 % |
| Circumference | 72.0" | 72.7" | +0.9 % |
| Revs per mile | 880 | 872 | -0.9 % |
| Axle height | 11.46" | 11.57" | +2.8 mm |
| Approved rim width | 6–8" | 5.5–7" | overlap 6–7" |
Both are approved on a rim 6" to 7" wide. If yours is in that band, this is a tire change and nothing else.
What the speedometer will say
Calibrated for 215/35R17. Fit 195/40R17 and the needle stops telling the truth.
| Needle says | You are doing | Out by |
|---|---|---|
| 30 mph | 30.3 mph | +0.3 |
| 50 mph | 50.5 mph | +0.5 |
| 70 mph | 70.7 mph | +0.7 |
| 90 mph | 90.9 mph | +0.9 |
The odometer drifts with it. Ten thousand miles on the dial are really 10,094 on the road, so it under-counts by 94. At a true 70 mph the first turns 1026 times a minute, the second 1017.